TextMate uses a variety of helper scripts and applications in executing its commands. If you update your editions of these (install Python3000, Ruby 1.9), you may end up with "unexpected" behavior.

For example, an install of Python 3000 via Darwinports placed 'python' in my '/opt/local/bin'. This took precedence over the system standard '/usr/bin/python'. I tripped over this error when trying to use the LaTeX Bundle's "Typeset and View" command. While the pop-up said "Typesetting $Filename...," nothing ever returned. Only after debugging did I see that the command was calling a Python script that, it turns out, was using a non-backwards compatible interpreter.

Just make very sure you know what your path is and that you know that you're using safe interpreters.